Interoperability between wireless devices isn't a sure thing
Just when you thought it was safe to dive into the wireless networking world, it appears the waters aren't as calm as they seem. I hadn't received any email about problems with 802.11x wireless devices in quite a few months when suddenly a half-dozen messages from different readers popped into my Inbox, all asking similar questions. Each reader was having interoperability problems when moving between wireless networks with different vendor hardware, or performance problems with new wireless hardware.
My correspondents were all knowledgeable users, and their messages recounted tales of using the tips I've presented in the past, plus a few tricks I hadn't heard of, to no avail. A careful comparison of the details in all the messages revealed a common factor: All these readers were using equipment based on the 802.11g wireless standard. If you haven't been keeping up with wireless networking, the 802.11g specification is for 54Mbps wireless network--it's similar to the 802.11a standard but has the added benefit of compatibility with the 11Mbps 802.11b standard.
My discovery solved the performance problem question for me, so I quickly sent a message back to each reader. The responses I received confirmed my suspicions: Each reader was on a network that had users running 802.11b network adapters. When an 802.11g device senses the presence of 802.11b devices, it slows down to 11Mbps for compatibility. So, the readers who were attempting a gradual upgrade of their wireless networks weren't seeing any benefit from using new hardware, nor would they until all of the legacy wireless networking devices were off the networks. One reader replied that he would need to stop a corporatewide wireless upgrade; about 10 months previously, his company had upgraded its entire sales force to notebook computers with built-in 802.11b wireless networking. He had thought that he could gradually move to the faster wireless standard but now felt he had to reconsider the expense of doing so if his company wouldn't see any benefit until the next round of notebook upgrades, which was at least 18 months down the road.
Regarding the question of incompatibility among vendor hardware, these readers are bleeding edge and had purchased products according to the 802.11g draft specification, which is bound to change quickly over time. I don't know the specific differences the readers found between the different devices they were using, but the differences were enough to prevent communication between the devices. Testing for interoperability is happening industrywide; I expect the problems to be ironed out quickly.
On the plus side, the advent of 802.11a and 802.11g technologies have brought the price of reliable 802.11b products down sharply. If you haven't taken the plunge into wireless networking, you can start with 802.11b products without breaking the bank.